This invention is directed to the field of concrete block construction and, in particular, to retainer device that allows for the inspection of steel reinforcement and concrete core filling.
The technique of reinforcing hollow concrete blocks is a well accepted building practice for use where added wall strength is necessary. Steel reinforced concrete and masonry construction provides numerous benefits over other construction systems including resistance to insect infestation and decomposition due to moisture and other environmental exposure. Reinforced concrete masonry is commonly incorporated into very economically and environmentally efficient wall systems. Reinforcing hollow concrete block with steel rods embedded therein is ideal for use in buildings prone to abnormally severe environmental conditions, such as high winds due to hurricanes. Geographical areas such as Florida and other coastalregions prone to high winds, have adopted strong building construction codes and regulations regarding reinforced concrete block and the inspection thereof.
Current practices include the use of steel reinforcement bars, commonly referred to as rebar, that are placed into the hollow-core concrete blocks and anchored to a concrete foundation or footing. The concrete foundation includes reinforcing rods, either embedded therein or including a means for securing thereto, wherein the rebar extends vertically upward into concrete block walls and horizontally at beams, and spaced apart at distances established by structural calculation and local building codes. Such rebar may be placed at intervals from sixteen inches to eight feet, and at each comer of a wall structure, and beside each opening, depending upon the height of the wall and other factors of the structure. To ensure that building regulations are met, building inspectors view the wall to foundation securement through inspection holes through one face of the concrete block. The inspection holes must be securely covered during the concrete filling of the hollow-block wall, the concrete permanently fixing the rebar in position, and the cover retaining the concrete within the block cells.
Currently there are several methods for preparing an inspection viewing port. The viewing port may be formed by cutting a hole through the concrete block by use of a saw, chipping a hole through the concrete block by use of a mason""s hammer, or by use of a specialty concrete block being formed during manufacture. Said openings are formed for the purpose of inspection of the steel reinforcement and subsequent filling of the block cell with concrete.
A basic inspection hole must be covered after inspection by a plate made of plastic, wood, or any other suitable rigid material. Most commonly pieces of plywood are placed over each hole and fastened to the surrounding block with certain nails driven with a hammer or by pneumatic gun. The nails often crack the surrounding block surface. Should the weakened patch fail while concrete is being inserted, the results would be the loss of a cubic yard or more of concrete, time and labor to remove the wasted concrete, and possibly further delay of the work. Nailed-on plywood inspection hole covers have other disadvantages. Installation and removal of plywood covers is time consuming. The pneumatic gun requires an air compressor and electric power. The air hoses must be dragged around the building""s entire perimeter. Plywood covers can be used twice without removal of nails from prior use. In order to use plywood covers a third time, nails from at least one prior use must be removed by hand. Transport, handling, and storage of plywood covers with protruding nails is difficult.
Due to the disadvantages associated with nailed-on plywood inspection plate covers, a number of attempts have been made to provide alternative closure techniques pertaining to the inspection port securement. U.S. Pat. No. 5,065,560 discloses a concrete block inspection form which consists of a specially manufactured hollow concrete block having a preformed opening. The block is sold as a kit which includes an inspection plate cover that is sized for the preformed opening. The disadvantages of such preformed block are the added expense required for the specialty concrete block which also include special care and shipping. Since these blocks are used only for inspection, the exact number of blocks must be calculated for extra blocks would be discarded or need to be returned. However, if the exact number of blocks is ordered, should any block be damaged during installation, additional blocks may need to be ordered which could delay construction. Further, the modified concrete block is not suitable for all installations as a portion of the wall has been removed.
U.S. Pat. No. 5,269,114 discloses yet another cover retainer for a concrete block inspection plate. This invention includes the use of a flange that fits inside the opening of the concrete block, and is rotated so as to engage the inner sidewalls of the concrete block with an attachment nut securing an outer cover plate, which engages the outer surface of the concrete block in a proximal relationship to the wall. In this manner concrete may be placed through the hollow concrete block, where it forms around the securement mechanism. Once the concrete has solidified, the cover may be removed by disengaging the threaded locking nut from the plate and removing the plate from the outer surface of the sidewall. This device does not address various size openings, and is limited to engaging those openings that have clear access along the inner wall, and have a predetermined width regarding the opening for placement therein. This device also requires the concrete block to be preformed, which again adds to the expense of installation by requiring pre-made concrete blocks with openings of a predetermined size. The associated risk for installation of precut blocks remains the same, and shipment requires additional care to prevent premature damage of the blocks.
Thus, what is needed in the art is a retainment system for inspection port covers allowing for flexibility with respect to position of the reinforcing rod, and in the size of inspection holes, and thus, the method of creating the hole, thereby eliminating the need for specially cut or formed blocks and the associated costs for shipping, storing, and placement. In addition, the method must be strong and relatively failsafe in containment of the concrete fill. Also needed is a system simple to install, dismantle, and store for reuse.
The instant invention consists of shaft having annular grooves and a hook shaped end. The device is positioned with hooked end around the rebar, extending through the inspection hole into and through the aperture of a cover plate. In the primary embodiment, the cover plate consists of a flat plate with an offset disposed aperture. The cover plate incidentally will be made of clear plastic providing rigidity and transparency. A U-shaped nut is then employed having grooves to engage the annular grooves of the shaft thereby coupling the nut to the shaft. In this manner, the closure plate is held securely in place by the nut, frictionally engaging the plate against the outer wall surface of the concrete block, prohibiting poured concrete from flowing therethrough. The use of the clear plastic plate further allows for additional inspection of the rebar before and during pouring of the concrete.
In another embodiment, the clear plastic plate includes a slot having annular grooves for engaging the annular grooves on the shaft. The second embodiment eliminates the need for a secondary nut and is useful when horizontal access to the inspection hole is available.
Yet another embodiment includes the use of a hook-shaped shaft having directional tabs. In this embodiment, the shaft is placed through an aperture of a cover plate where the directional tabs engage the cover plate during the sliding of the cover plate, thereby securing the plate in juxtaposition to the outer surface of the concrete block.
Each of the embodiments include a grooved shaft that allow the excess portion of the shaft to be broken free once the concrete has cured. The annular grooves provide various disengagement points along the length thereof, wherein the exact length is determined after the concrete has been poured. Removal of the inspection plate simply requires the use of a hammer to cause breakage of the shaft along the surface of the concrete providing smooth flush surface that can be stucco over without further preparation.
Thus, an objective of the instant invention is to provide an apparatus for ease of covering an inspection hole in a concrete block installation.
Yet another objective of the instant invention is to provide a cost effective method of closure over viewing ports for inspection of reinforcement steel that is universal in application, does not require preformed inspection blocks or form-fitting inspection plate covers.
Still another objective of the instant invention is to provide a retainment device that secures directly to the reinforcement steel, regardless of various reinforcement positions, said retainment device allowing full flow around the reinforcement steel and within the block cavity.
Yet still another objective of the instant invention is to provide various locking embodiments that allow the use of a various sized inspection holes and plate, or pre-sized inspection plates wherein the locking nut is incorporated thereto.
Still another objective of the instant invention is to readily retain over the inspection port, a clear access plate cover providing an uninhibited view to the steel reinforcement and to verify steel reinforcement positioning before and while concrete is being inserted, and to observe that concrete has flowed fully to the bottom of the cell, ensuring that no obstruction has prevented such.
Other objectives and advantages of this invention will become apparent from the following description taken in conjunction with the accompanying drawings wherein are set forth, by way of illustration and example, certain embodiments of this invention. The drawings constitute a part of this specification and include exemplary embodiments of the present invention and illustrate various objects and features thereof.